JPH08320557A - Photosensitive composition and photosensitive planographic printing plate - Google Patents

Abstract

PURPOSE: To obtain a photosensitive compsn. having improved printing resistance as well as high sensitivity and improved development latitude and to obtain a photosensitive planographic printing plate using the compsn. CONSTITUTION: This photosensitive compsn. contains an o-quinonediazide compd., an alkali-soluble resin and a mixed solvent consisting of at least one selected from among diethyl ketone, isobutyl acetate and methyl isobutyl ketone and at least one selected from among diethyl carbitol, 3-methoxy-1-butanol, dipropyleneglycolmonomethyl ether, methyl lactate, ethyl lactate, propyleneglycolmonomethyl ether, diethyleneglycoldimethyl ether, ethyl cellosolve and methyl cellosolve.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive composition and a photosensitive lithographic printing plate, and more particularly to a positive type photosensitive composition and a photosensitive lithographic printing plate which are compatible with printing durability, high sensitivity and development acceptability.

[0002]

BACKGROUND OF THE INVENTION Conventionally, as a photosensitive composition for a positive type photosensitive lithographic printing plate, a composition containing an alkali-soluble resin and a naphthoquinonediazide compound as a photosensitive material is generally used. For example, novolac type phenolic resin /
Naphthoquinonediazide-substituted compounds as US Pat.
666,473, U.S. Pat. No. 4,115,128 and U.S. Pat. No. 4,173,470, and the most typical composition of cresol-formaldehyde is a novolac resin / trihydroxybenzophenone-.
An example of 1,2-naphthoquinonediazide sulfonate is Thompson "Introduction to Microlithography" (ACS Publishing, No. 219, p1).
12-121).

Many positive-working photosensitive lithographic printing plates containing the above-mentioned novolac resin and naphthoquinonediazide type photosensitive material have been developed and put into practical use. In this type of positive-type photosensitive lithographic printing plate, as a method of increasing the alkali solubility, alkali-soluble resin, naphthoquinonediazide molecular weight down of the photosensitive material, reduce the amount of the photosensitive material in the photosensitive layer, organic acids, inorganic acids, It is known to add acid anhydrides, but this method causes problems such as deterioration of film strength, lowering of chemical resistance and resistance to ballpoint pens, and narrowing of the range of appropriate developing conditions. It was

[0004]

OBJECTS OF THE INVENTION The object of the present invention is (1) high sensitivity, (2) improved development allowance, and (3) a photosensitive composition and a photosensitive lithographic plate which are compatible with the above performance and printing durability. It is to provide a print version.

[0005]

The above-mentioned problems of the present invention are as follows. (A) an o-quinonediazide compound, (B) an alkali-soluble resin, and (C) at least one selected from diethyl ketone, isobutyl acetate, and methyl isobutyl ketone, diethyl carbitol, and 3-methoxy-1.
-Butanol, dipropylene glycol monomethyl ether, methyl lactate, ethyl lactate, propylene glycol monomethyl ether, diethylene glycol dimethyl ether, ethyl cellosolve, a photosensitive composition characterized by containing at least one mixed solvent selected from methyl cellosolve,

2. (A) o-quinonediazide compound,
(B) an alkali-soluble resin and (C) a mixture composition of methyl ethyl ketone and two or more selected from methyl isobutyl ketone, isobutyl acetate, ethyl cellosolve, and methyl cellosolve, a photosensitive composition comprising:

3. A photosensitive lithographic printing plate comprising the photosensitive composition as described in 1 or 2 above.

[0008]

The present invention can solve the above problems that cannot be solved by the prior art by using the specific mixed solvent described in the above claims.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in more detail below. The aluminum support used in the present invention includes a support made of pure aluminum and an aluminum alloy. Various aluminum alloys can be used, for example, an alloy of aluminum with a metal such as silicon, copper, manganese, magnesium, chromium, zinc, lead, bismuth, or nickel.

The aluminum support is preferably subjected to a degreasing treatment in order to remove rolling oil on the aluminum surface prior to roughening. As degreasing treatment, trichlene,
A degreasing treatment using a solvent such as thinner, an emulsion degreasing treatment using an emulsion such as kesilon and triethanol, and the like are used. In addition, an alkaline aqueous solution such as caustic soda can be used for the degreasing treatment. When an alkaline aqueous solution such as caustic soda is used for the degreasing treatment, it is possible to remove stains and oxide films which cannot be removed only by the above degreasing treatment.

As a graining treatment method carried out to improve the adhesion to the photosensitive layer and to improve the water retention,
There are a so-called mechanical surface-roughening method for mechanically roughening the surface and a so-called electrochemical surface-roughening method for electrochemically roughening the surface. Examples of the mechanical surface roughening method include ball polishing, brush polishing, blast polishing, and buff polishing. The electrochemical surface roughening method includes, for example, a method of electrolytically treating the support with an alternating current or a direct current in an electrolytic solution containing hydrochloric acid, nitric acid, or the like. One of these
One or a combination of two or more methods makes it possible to grain the support.

Since smut is formed on the surface of the support obtained by the graining treatment as described above, it is generally necessary to appropriately perform washing with water or alkali etching to remove the smut. preferable. Examples of such a treatment include the alkaline etching method described in Japanese Patent Publication No. 48-28123 and Japanese Patent Laid-Open No. 53-53.
Examples thereof include a treatment method such as a sulfuric acid desmutting method described in 12739.

The support usually has abrasion resistance, chemical resistance,
An oxide film is formed by anodic oxidation in order to improve water retention. In this anodic oxidation, generally, a method of electrolyzing with an aqueous solution containing sulfuric acid and / or phosphoric acid or the like at a concentration of 10 to 50% at a current density of 1 to 10 A / dm ² is preferably used. Patent No. 1,41
There are a method of electrolyzing in sulfuric acid at a high current density described in 2,768, a method of electrolyzing using phosphoric acid described in US Pat. No. 3,511,661, and the like.

The support may be subjected to a pore-sealing treatment after the anodizing treatment. Examples of the sealing treatment include boiling water treatment, steam treatment, sodium silicate treatment, dichromate aqueous solution treatment, nitrite treatment, and ammonium acetate treatment.

Further, the support may be provided with a hydrophilic undercoat layer. As the hydrophilic undercoat layer, U.S. Pat. No. 3,181,4 is used.
61, alkali metal silicates, hydrophilic celluloses described in U.S. Pat. No. 1,860,426, JP-A-60-149491 and 63-165.
183, amino acids and salts thereof, JP-A-60
-Amines and salts thereof having a hydroxyl group described in JP-A-232998, a phosphate salt described in JP-A-62-19494, and a high content containing a monomer unit having a sulfo group described in JP-A-59-101651. Examples thereof include molecular compounds.

Next, a photosensitive layer containing the photosensitive composition of the present invention (claim 1 or 2) described below is coated on the surface-treated support and dried to obtain the photosensitive lithographic plate of the invention. A printing plate (claim 3) is obtained. The photosensitive substance used in this photosensitive layer contains the following o-quinonediazide compound, an alkali-soluble resin and a mixed solvent described below, and other substances are not particularly limited.
Various materials generally used for photosensitive lithographic printing plates can be used. Hereinafter, this point will be described.

(Photosensitive layer) (Photosensitive composition containing o-quinonediazide compound) The o-quinonediazide compound used in the positive photosensitive composition layer of the present invention is a compound having an o-quinonediazide compound in its molecule. The o-quinonediazide compound that can be used in the present invention is not particularly limited, and for example, a polycondensation resin having an o-quinonediazide group, for example, o-naphthoquinonediazidesulfonic acid,
Examples thereof include ester compounds with polycondensation resins of phenols and aldehydes or ketones.

Examples of the phenols include monohydric phenols such as phenol, o-cresol, m-cresol, p-cresol, 3,5-xylenol, carvacrol and thymol, and dihydric compounds such as catechol, resorcinol and hydroquinone. Examples include trihydric phenols such as phenol, pyrogallol, and phloroglucin. Examples of the aldehyde include formaldehyde, benzaldehyde, acetaldehyde, crotonaldehyde, and furfural. Preferred of these are formaldehyde and benzaldehyde. Examples of the ketone include acetone and methyl ethyl ketone.

Specific examples of the polycondensation resin include phenol / formaldehyde resin, m-cresol / formaldehyde resin, m- and p-mixed cresol / formaldehyde resin, resorcin / benzaldehyde resin, pyrogallol / acetone resin. To be OH of phenols of the o-naphthoquinonediazide compound
The condensation rate of o-naphthoquinonediazide sulfonic acid with respect to the group (reaction rate with respect to one OH group) is preferably 15 to 80%, and more preferably 20 to 45%.

Further, as the o-quinonediazide compound used in the present invention, the following compounds described in JP-A-58-43451 can also be used. That is, for example, 1, 2
-Benzoquinone diazide sulfonate, 1,2-
Known 1,2-naphthoquinone diazide sulfonic acid ester, 1,2-benzoquinone diazide sulfonic acid amide, 1,2-naphthoquinone diazide sulfonic acid amide, etc.
Quinone diazide compounds, more specifically J. Kosar "Light-Sensitive Systems" (Light-Sensitive System)
ems) pp. 339-352 (1965), John.
Willie & Sons (John Willey &
Sons, Inc. (New York) and W. S. De Forest, "Photoresist", Volume 50 (1975), McGraw H
ill) (New York) 1,2-
Benzoquinonediazide-4-sulfonic acid phenyl ester, 1,2,1 ', 2'-di- (benzoquinonediazide-4-sulfonyl) -dihydroxybiphenyl, 1,2
-Benzoquinonediazide-4- (N-ethyl-M-β-
Naphthyl) -sulfonamide, 1,2-naphthoquinonediazide-5-sulfonic acid cyclohexyl ester, 1-
(1,2-naphthoquinonediazide-5-sulfonyl)-
3,5-Dimethylpyrazole, 1,2-naphthoquinonediazide-5-sulfone-4'-hydroxydiphenyl-
4'-azo-β-naphthol-ester, N, N-di-
(1,2-naphthoquinonediazide-5-sulfonyl)-
Aniline, 2 '-(1,2-naphthoquinonediazide-5
-Sulfonyloxy) -1-hydroxy-anthraquinone, 1,2-naphthoquinonediazide-5-sulfone-
2,4-dihydroxybenzophenone ester, 1,2
-Naphthoquinonodiazide-5-sulfonic acid-2,3,4
-Trihydroxybenzophenone ester, a condensate of 2 mol of 1,2-naphthoquinonediazide-5-sulfonic acid chloride and 1 mol of 4,4'-diaminobenzophenone,
Condensate of 2 mol of 1,2-naphthoquinonediazide-5-sulfonic acid chloride and 1 mol of 4,4′-dihydroxy-1,1′-diphenylsulfone, 1 mol of 1,2-naphthoquinonediazide-5-sulfonic acid chloride Examples thereof include a 1,2-quinonediazide compound such as a condensate of 1 mol of purpurogallin and 1,2-naphthoquinonediazide-5- (N-dihydroabietyl) -sulfonamide. In addition, Japanese Examined Patent Publications No. 37-1953 and 37-3627
Nos. 37-13109, 40-26126, 40-3801, 45-5604, 45-27.
No. 345, No. 51-13013, JP-A-48-965.
The 1,2-quinonediazide compounds described in JP-A No. 75, 48-63802 and 48-63803 can also be mentioned.

Of the above o-quinonediazide compounds,
An o-quinone diazide ester compound obtained by reacting 1,2-benzoquinone diazide sulfonyl chloride or 1,2-naphthoquinone diazide sulfonyl chloride with pyrogallol-acetone condensation resin or 2,3,4-trihydroxybenzophenone is particularly preferable. As the o-quinonediazide compound used in the present invention, the above compounds may be used alone or in combination of two or more kinds. The proportion of the o-quinonediazide compound in the photosensitive composition is preferably 5 to 60% by weight, and particularly preferably 10 to 50% by weight.

(Alkali-Soluble Resin) Examples of the alkali-soluble resin used in the photosensitive composition of the present invention include novolac resins, vinyl polymers having a phenolic hydroxyl group, and many of them described in JP-A-55-57841. Examples thereof include a condensation resin of a polyhydric phenol and an aldehyde or a ketone.

Examples of the novolac resin used in the present invention include phenol / formaldehyde resin, cresol / formaldehyde resin, JP-A-55-57841.
Phenol-cresol-formaldehyde copolymer resin as described in JP-A-55-127
Examples thereof include copolymer resins of p-substituted phenol and phenol or cresol and formaldehyde as described in Japanese Patent No. 553.

The novolak resin preferably has a number average molecular weight Mn of 3.00 × (polystyrene standard).
10 ^{2 to} 7.50 × 10 ³ , and the weight average molecular weight Mw is 1.
00 × 10 ^{3 to} 3.00 × 10 ⁴ , more preferably Mn
Is 5.00 × 10 ^{2 to} 4.00 × 10 ³ , and Mw is 3.0.
It is 0 × 10 ^{3 to} 2.00 × 10 ⁴ . The above novolak resins may be used alone or in combination of two or more. The proportion of the novolak resin in the photosensitive composition is preferably 5 to 95% by weight. Further, the vinyl copolymer having a phenolic hydroxyl group preferably used in the present invention is a polymer having a unit having the phenolic hydroxyl group in the molecular structure, and is represented by the following general formula [I] to
Polymers containing at least one structural unit of [V] are preferred.

[0025]

Embedded image

[In the formula, R ₁ and R ₂ each represent a hydrogen atom, an alkyl group or a carboxyl group, preferably a hydrogen atom. R ₃ represents a hydrogen atom, a halogen atom or an alkyl group, preferably a hydrogen atom or an alkyl group such as a methyl group or an ethyl group. R ₄ represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group, preferably a hydrogen atom. A represents an optionally substituted alkylene group connecting a nitrogen atom or an oxygen atom and an aromatic carbon atom, m represents an integer of 0 to 10, and B represents
Represents a phenylene group which may have a substituent or a naphthylene group which may have a substituent. ]

As the polymer used in the present invention, those having a copolymer type structure are preferable, and the above-mentioned general formula [I] is used.
~ Examples of the monomer unit that can be used in combination with the structural unit represented by the general formula [V] include ethylenically unsaturated offylenes such as ethylene, propylene, isobutylene, butadiene, and isoprene, for example, styrene and α-. Styrenes such as methylstyrene, p-methylstyrene and p-chlorostyrene, acrylic acids such as acrylic acid and methacrylic acid, and unsaturated aliphatic dicarboxylic acids such as itacone, maleic acid and maleic anhydride,
For example, methyl acrylate, ethyl acrylate, -n-butyl acrylate, isobutyl acrylate, dodecyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloroacrylate, methyl methacrylate, ethyl methacrylate, Α such as ethyl methacrylate
-Esters of methylene aliphatic monocarboxylic acid, for example, nitriles such as acrylonitrile, methacrylonitrile, etc., amides such as acrylamide, such as acrylanilide, p-chloroacrylanilide, m-nitroacrylanilide, m-methoxyacrylanilide, etc. Anilides such as vinyl acetate, vinyl propionate,
Vinyl esters such as vinyl benzoate and vinyl acetate,
For example, methyl vinyl ether, ethyl vinyl ether,
Isobutyl vinyl ether, vinyl ethers such as β-chloroethyl vinyl ether, vinyl chloride, vinylidene chloride, vinylidene cyanide, such as 1-methyl-1-methoxyethylene, 1,1-dimethoxyethylene, 1,2-dimethoxyethylene, 1,1 -Dimethoxycarbonylethylene, ethylene derivatives such as 1-methyl-1-nitroethylene, such as N-vinylpyrrole, N
There are N-vinyl type monomers such as -vinylcarbazole, N-vinylindole, N-vinylpyrrolidene and N-vinylpyrrolidone. These vinyl-based monomers are present in the polymer compound with a structure in which the unsaturated double bond is cleaved.

Of the above monomers, aliphatic monocarboxylic acid esters and nitriles are preferable because they exhibit excellent performance for the purpose of the present invention. These monomers may be bound to the polymer used in the present invention in either a block or random state. The proportion of the vinyl polymer used in the present invention in the photosensitive composition is 0.5 to
Preferably, it is 70% by weight. The vinyl polymer is
The above polymers may be used alone or in combination of two or more. It can also be used in combination with other polymer compounds.

(Organic Acid / Inorganic Acid / Anhydride) The photosensitive composition of the present invention may contain an organic acid / inorganic acid / anhydride. Examples of the acid used in the present invention include organic acids described in JP-A No. 60-88942 and Japanese Patent Application No. 63-293107, and "Chemical Handbook New Edition" edited by The Chemical Society of Japan, No. 92-158. The inorganic acids described on the page can be mentioned.
Examples of organic acids include p-toluenesulfonic acid, dodecylbenzenesulfonic acid, mesitylenesulfonic acid, methanesulfonic acid, ethanesulfonic acid, benzensulfonic acid,
Sulfonic acids such as m-benzenedisulfonic acid, sulfinic acids such as p-toluenesulfinic acid, benzylsulfinic acid and methanesulfinic acid, phosphonic acids such as phenylphosphonic acid, methylphosphonic acid and chloromethylphosphonic acid,
Aliphatic monocarboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, pentanoic acid, hexanoic acid and heptanoic acid, alicyclic monocarboxylic acids such as cyclohexanecarboxylic acid, benzoic acid, o-, m-, p -Hydroxybenzoic acid,
o-, m-, p-methoxybenzoic acid, o-, m-, p-
Aromatic monocarboxylic acids such as methylbenzoic acid, 3,5-dihydroxybenzoic acid, phloroglysin carboxylic acid, gallic acid and 3,5-dimethylbenzoic acid can be mentioned. Also,
Saturated or unsaturated aliphatic dicarboxylic acids such as malonic acid, methylmalonic acid, dimethylmalonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, itaconic acid, malic acid, tetrahydro Phthalic acid, 1,1-cyclobutanedicarboxylic acid,
1,1-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,1-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3
Examples thereof include alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid and aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid.

Among the above organic acids, more preferable one is p
-Toluenesulfonic acid, dodecylbenzenesulfonic acid,
Examples include sulfonic acid such as mesitylenesulfonic acid, methanesulfonic acid, ethanesulfonic acid, benzensulfonic acid, and m-benzenedisulfonic acid, cis-1,2-cyclohexanedicarboxylic acid, and syringic acid. Examples of the inorganic acid include nitric acid, sulfuric acid, hydrochloric acid, silicic acid, phosphoric acid and the like, more preferably sulfuric acid and phosphoric acid.

When an acid anhydride is used, the type of acid anhydride is also arbitrary, and those derived from aliphatic / aromatic monocarboxylic acids such as acetic anhydride, propionic anhydride, benzoic anhydride, and succinic anhydride. , Maleic anhydride, glutaric anhydride, phthalic anhydride, and the like, and the like derived from aliphatic / aromatic dicarboxylic acids. Preferred acid anhydrides are glutaric anhydride and phthalic anhydride. These compounds may be used alone or in combination of two or more. The content of these acids is generally 0.05 to 5% by weight, and preferably 0.1 to 3% by weight, based on the total solid content of the entire photosensitive composition.

(Surfactant) The photosensitive composition of the present invention may contain a surfactant. As the surfactant, an amphoteric surfactant, an anionic surfactant, a cationic surfactant,
Nonionic surfactants, fluorine-based surfactants and the like can be mentioned.

Examples of the amphoteric surfactant include lauryl dimethylamine oxide, lauryl carboxymethyl hydroxyethyl, imidazolinium betaine and the like.
As the anionic surfactant, a fatty acid salt, an alkyl sulfate ester salt, an alkylbenzene sulfonate, an alkylnaphthalene sulfonate, an alkylsulfosuccinate,
Examples thereof include alkyl diphenyl ether disulfonate, alkyl phosphate, polyoxyethylene alkyl sulfate ester salt, polyoxyethylene alkyl allyl sulfate ester salt, naphthalene sulfonic acid formalin condensate, and polyoxyethylene alkyl phosphate ester. Examples of cationic surfactants include alkylamine salts, quaternary ammonium salts, and alkyl betaines. As the nonionic surfactant, polyoxyethylene alkyl ether,
Polyoxyethylene alkyl allyl ether, polyoxyethylene derivative, oxyethylene / oxypropylene block copolymer, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, glycerin fatty acid ester, polyoxyethylene fatty acid ester, polyoxy Examples include ethylene alkylamines and alkyl alkanolamides.

Examples of the fluorine-containing surfactant include copolymers of acrylates or methacrylates containing a fluoroaliphatic group and (polyoxyalkylene) acrylates or (polyoxyalkylene) methacrylates. For example, JP-A Nos. 62-170950 and 62-2.
26143, U.S. Pat. No. 3,787,351 and the like (for example, Megafac F-171,173,1).
77, Defencer MCF300, 312, 313 (all manufactured by Dainippon Ink and Chemicals, Inc.), Modiper F-10
0, 102, 110 (manufactured by NOF CORPORATION) and the like. These compounds may be used alone or in combination of two or more. The proportion in the photosensitive composition is preferably 0.01 to 10% by weight, more preferably 0.01 to 5% by weight.

(Printout Material) A printout material capable of forming a visible image upon exposure can be added to the photosensitive composition. The printout material comprises an organic dye which changes its color tone by interacting with a compound which forms an acid or a free radical upon exposure. Examples of the compound which forms an acid or a free radical upon exposure include, for example, JP-A-50- O described in Japanese Patent No. 36209
-Naphthoquinonediazide-4-sulfonic acid halogenide,
An ester compound or amide compound of o-naphthoquinonediazide-4-sulfonic acid chloride and an electron-withdrawing substituent phenol or aniline acid described in JP-A-53-36223, JP-A-55-
Examples thereof include halomethylvinyloxadiazole compounds and diazonium salts described in JP-A 77742, JP-A-57-148784 and the like.

(Compound which produces an acid or a free radical upon exposure to light) As a compound which can be used in the photosensitive composition of the present invention to produce an acid or a free radical upon exposure, for example, a halomethyloxadiazole compound, A halomethyl-s-triazine compound or the like is used. The halomethyl oxadiazole compound is a compound having halomethyl group, preferably trichloromethyl group, in oxadiazoles.

These compounds are known, for example, Japanese Patent Publication Nos. 57-6096 and 61-51788,
Japanese Patent Publication No. 1-28369, JP-A-60-13853
No. 9, JP 60-177340, and JP 60-24.
It is described in Japanese Patent No. 1049. In addition, the halomethyl-s-triazine compound is a compound having one or more halomethyl groups, preferably a trichloromethyl group, in the s-triazine ring.

In the photosensitive composition of the present invention, the addition amount of the compound capable of forming an acid or a free radical upon exposure to light is 0.
01 to 30% by weight is preferable, and 0.1 is more preferable.
10 to 10% by weight, particularly preferably 0.2 to 3% by weight. These compounds may be used alone or in combination of two or more.

(Dye) A dye may be further used in the photosensitive composition of the present invention. The dye is used for the purpose of obtaining a visible image by exposure (exposed visible image) and a visible image after development.

As the dye, those which change color tone by reacting with free radicals or acids can be preferably used.
Here, "the color tone changes" includes both a change from colorless to a color tone, and a change from a colored to a colorless or different color tone. Preferred dyes are those which form a salt with an acid to change the color tone. For example, Victoria Pure Blue BOH (Hodogaya Chemical Co., Ltd.), Oil Blue #
603 (manufactured by Orient Chemical Industry Co., Ltd.), patent pure blue (manufactured by Sumitomo Mikuni Chemical Co., Ltd.), crystal violet,
Brilliant Green, Ethyl Violet, Methyl Violet, Methyl Green, Erythrosin B, Pesic Fuchsin, Malachite Green, Oil Red, m
-Cresol purple, rhodamine B, auramine,
Triphenylmethane-based, diphenylmethane-based, oxazine-based, xanthene-based, iminonaphthoquinone-based, azomethine-based, or anthraquinone-based dyes such as 4-p-diethylaminophenyliminaquinoquine and cyano-p-diethylaminophenylacetanilide are colored to colorless. Alternatively, it may be mentioned as an example of a color changing agent that changes to a different color tone.

On the other hand, examples of the discoloring agent that changes from colorless to colored include leuco dyes and, for example, triphenylamine, diphenylamine, o-chloroaniline, 1,2,3-triphenylguanidine, naphthylamine, diaminodiphenylmethane, p, p. ′ -Bis-dimethylaminodiphenylamine, 1,2-dianilinoethylene, p, p ′,
p ″ -tris-dimethylaminotriphenylmethane,
p, p'-bis-dimethylaminodiphenylmethylimine, p, p ', p "-triamino-o-methyltriphenylmethane, p, p'-bis-dimethylaminodiphenyl-4-anilinonaphthylmethane, p, Examples thereof include primary or secondary arylamine dyes represented by p ′, p ″ -triaminotriphenylmethane. The proportion of the above-mentioned discoloring agent in the photosensitive composition is preferably 0.01 to 10% by weight, more preferably 0.02 to
Used at 5% by weight. These compounds may be used alone or in combination of two or more. Particularly preferred dyes are Victoria Pure Blue BOH and Oil Blue # 6.
It is 03.

(Oil-sensitizer) An oil-sensitizer for improving the oil-sensitivity of the image area (for example, a half-esterified product of an alcohol of a styrene-maleic anhydride copolymer described in JP-A-55-527). , Pt-butylphenol-
Novolak resins such as formaldehyde resins, or partial esterification products of these with o-quinonediazide compounds, fluorine-based surfactants, p-hydroxystyrene 5
0% fatty acid ester, etc.) are preferably used. The amount of these additives added varies depending on the object of use and purpose, but is generally 0.01 to 30% by weight based on the total solid content. Dissolve each of these components in the following solvent,
By coating on the surface of the support and drying, a photosensitive layer can be provided to produce the photosensitive lithographic printing plate of the invention. There is no special limitation on the usage of the solvent.

(Coating Solvent) As a coating solvent (solvent) for the photosensitive composition, the following mixed solvent is used. Claim 1
In the present invention shown in, at least one selected from diethyl ketone, isobutyl acetate, methyl isobutyl ketone, and diethyl carbitol, 3-methoxy-1-butanol, dipropylene glycol monomethyl ether, methyl lactate, ethyl lactate, propylene glycol monomethyl. At least one mixed solvent selected from ether, diethylene glycol dimethyl ether, ethyl cellosolve, and methyl cellosolve is used. The mixing ratio (% by weight) is preferably 70% or more for the former and 30% or less for the latter, more preferably 75 to 90% for the former and 10 to 25% for the latter.

In the present invention as set forth in claim 2, a mixed solvent of methyl ethyl ketone and two or more selected from methyl isobutyl ketone, isobutyl acetate, ethyl cellosolve and methyl cellosolve is used. The mixing ratio is 20-50% for methyl ethyl ketone and 50-80% for the latter.
Is preferred, and more preferably methyl ethyl ketone is 25
~ 45%, the latter 55-75%. In addition, in the present invention, other solvents may be contained within a range that does not impair the effects of the present invention.

(Coating Layer) In the photosensitive lithographic printing plate according to the present invention, a coating layer made of a water-insoluble organic solvent-soluble polymer compound having film forming ability can be formed on the photosensitive layer. A matte layer is preferably provided on the surface of the photosensitive layer provided as described above, in order to shorten the vacuuming time during contact exposure using a vacuum baking frame and prevent baking blur. Specifically, JP-A-50-1258
No. 05, Japanese Patent Publication No. 57-6582, No. 61-28986.
The method of providing a mat layer as described in each of the publications, the method of heat-bonding a solid powder as described in JP-B-62-62337 and the like can be mentioned.

(Matting agent) The purpose of the matte layer is to improve the vacuum adhesion between the image film and the photosensitive lithographic printing plate during contact exposure, thereby shortening the vacuuming time and, in addition, the fine mesh during exposure due to poor adhesion. It is to prevent the dots from collapsing. As a coating method of the matte layer, there is disclosed in Japanese Patent Laid-Open No. 55-
No. 12974 includes a method of heat-sealing powdered solid powder and a method of spraying polymer-containing water described in JP-A No. 58-182636 and drying, and any method may be used. It is desirable that the matte layer itself be soluble in an alkaline developer or be removable by this.

(Inclusion Compound) The inclusion compound which may be contained in the photosensitive composition according to the present invention will be described. The clathrate is a state in which a three-dimensional structure formed by combining atoms or molecules has voids, and another or molecules enter into the three-dimensional structure at a constant composition ratio to form a specific structure. Therefore, the clathrate compound refers to a compound having a property of incorporating another molecule or atom into the vacancy formed by itself. The driving force that causes this inclusion may be hydrophobic interaction, ionic interaction, hydrogen bond, van der Waals force, or the like. Specific examples of the inclusion compound, cyclodextrin, crown ether, cyclophane, azacyclophane, calixarene, cyclotriveratrylene, spherand, capitand, those having a clathrate ability in a single molecule such as a cyclic oligopeptide, Urea, thiourea, theoxycholic acid, apocholic acid, cholic acid, dinitrodiphenyl,
Hydroquinone, perhydrotriphenylene, tri-o-
Thymoid, oxyflavan, dicyanoammine nickel, dioxytriphenylmethane, methylnaphthalene,
Examples include multimolecular systems such as spirocoumarin and perhydrotriphenylene, which have an inclusion ability. Further, natural polymers such as cellulose, starch, chitin, chitosan, and proteins, and synthetic polymers such as polyvinyl alcohol also include various compounds. Most preferred are cyclodextrin and its derivatives, of which β
-Cyclodextrin and its derivatives are more preferred.
The ratio of these clathrate compounds in the photosensitive composition is 0.
01 to 10% by weight is preferable, and 0.1 to 5% by weight is more preferable. These compounds can be used alone or in combination of two or more.

(Coating) As a coating method used for coating the photosensitive composition or the coating layer or the mat layer on the surface of the support, conventionally known methods such as spin coating, wire bar coating, dip coating and air knife can be used. Coating, roll coating,
Blade coating and curtain coating are used.

(Exposure) In using the photosensitive lithographic printing plate thus obtained, a conventionally used method can be applied. For example, a transparent original image having a line image, a halftone image or the like is formed on the photosensitive surface. A relief image is obtained by exposing the film in close contact with it and then removing the photosensitive layer in the non-image area with a suitable developing solution. Suitable light sources for exposure include mercury lamps, metal halide lamps, xenon lamps,
Chemical lamps, carbon arc lamps, etc. are used.

(Processing) In the present invention, the developing solution and the developing replenishing solution used for the developing process of the photosensitive lithographic printing plate both contain an alkali metal silicate. The alkali metals of alkali metal silicates include lithium, sodium,
Potassium is included, of which potassium is most preferred. At the time of development, it is preferable that the development replenisher is appropriately replenished in accordance with the development processing amount of the photosensitive lithographic printing plate.

A preferred developing solution and developing replenishing solution are [SiO 2
₂ ] / [M] (in the formula, [SiO ₂ ] represents the molar concentration of SiO ₂ and [M] represents the molar concentration of alkali metal), and the SiO ₂ concentration is It is an aqueous solution of an alkali metal silicate that is 0.5 to 5.0% by weight based on the total weight. Further, it is particularly preferable that the developing solution [SiO
₂ ] / [M] is 0.25 to 0.75, the SiO ₂ concentration is 1.0 to 4.0% by weight, and the development replenisher [SiO ₂ ]
/ [M] is 0.15 to 0.5, and the SiO ₂ concentration is 1.0 to 3.0% by weight.

The above-mentioned developing solution and developing replenishing solution may contain water-soluble or alkali-soluble organic and inorganic reducing agents. Examples of the organic reducing agent include hydroquinone, metol, phenol compounds such as methoxyquinone, phenylenediamine, amine compounds such as phenylhydrazine, and the like, examples of inorganic reducing agents include sodium sulfite, potassium sulfite, and the like. Sulfites such as ammonium sulfite, sodium hydrogen sulfite, potassium hydrogen sulfite, sodium phosphite, potassium phosphite, sodium hydrogen phosphite, potassium hydrogen phosphite, sodium dihydrogen phosphite, potassium dihydrogen phosphite Phosphite, hydrazine, sodium thiosulfate, etc.
Examples thereof include sodium dithionite. These water-soluble or alkali-soluble reducing agents can be contained in the developing solution and the developing replenishing solution in an amount of 0.05 to 10% by weight. Further, the developing solution and the developing replenishing solution may contain an organic acid carboxylic acid. These organic acid carboxylic acids include aliphatic carboxylic acids having 6 to 20 carbon atoms and aromatic carboxylic acids having a benzene ring or a naphthalene ring substituted with a carboxyl group.

The aliphatic carboxylic acid has 6 to 2 carbon atoms.
Alkanoic acid of 0 is preferable, and specific examples thereof include caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, mistyric acid, palmitic acid,
Stearic acid and the like can be mentioned, with carbon number 6 being particularly preferred.
~ 12 alkanoic acids. Further, the aliphatic carboxylic acid may be a fatty acid having a double bond in the carbon chain or a fatty acid having a branched carbon chain. The aliphatic carboxylic acid may be used as a sodium or potassium salt or an ammonium salt.

Specific examples of the aromatic carboxylic acid include benzoic acid, o-chlorobenzoic acid, p-chlorobenzoic acid, o-hydroxybenzoic acid, p-hydroxybenzoic acid, p-tert-butylbenzoic acid, o-aminobenzoic acid, p-aminobenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 3,5
-Dihydroxybenzoic acid, gallic acid, 1-hydroxy-
2-naphthoic acid, 3-hydroxy-2-naphthoic acid, 2
-Hydroxy-1-naphthoic acid, 1-naphthoic acid, 2-
Naphthoic acid and the like can be mentioned.

The aromatic carboxylic acid may be used as a sodium or potassium salt or an ammonium salt. The content of the aliphatic carboxylic acid and the aromatic carboxylic acid may be at least 0.1 to 30% by weight. The developer and development replenisher may contain various anionic, nonionic and cationic surfactants and organic solvents. Furthermore, the developer and development replenisher should be
Known additives can be added.

[0056]

EXAMPLES The present invention will be described more specifically with reference to the following examples. (Preparation of support) An aluminum plate (material 1050, temper H16) having a thickness of 0.3 mm was degreased for 1 minute in a 5% sodium hydroxide aqueous solution kept at 65 ° C.
It was washed with water, immersed in a 10% sulfuric acid aqueous solution kept at 25 ° C. for 1 minute for neutralization, and further washed with water. This aluminum plate was electrolytically surface-roughened by an alternating current in a 1.8 wt% nitric acid aqueous solution under the conditions of a temperature of 25 ° C., a current density of 100 A / dm ² , and a treatment time of 60 seconds. Then, desmutting treatment is performed in a 5% aqueous sodium hydroxide solution at 60 ° C. for 10 seconds, and then in a 20% aqueous sulfuric acid solution at a temperature of 20 ° C.
The anodizing treatment was performed under the conditions of a current density of 3 A / dm ² and a treatment time of 1 minute. Then, it was immersed in a 1% sodium nitrite aqueous solution kept at 80 ° C. for 30 seconds, washed with water, and dried at 80 ° C. for 3 minutes. Further, after immersing in an aqueous solution of carboxymethylcellulose (concentration: 0.1 wt%) kept at 85 ° C for 30 seconds, it was dried at 80 ° C for 5 minutes to prepare a support.

(Photosensitive Solution A) Novolak resin (phenol / m-cresol / p-cresol molar ratio 10/54/36, weight average molecular weight 4000) 5.4 g pyrogallolacetone resin (weight average molecular weight 3000) and o -Naphthoquinone diazide-5-sulfonyl chloride condensate (esterification rate 30%) 1.5 g Acrylic resin (HYPMA / AN / EA / MMA molar ratio 30/30 / 3.5 / 36.5, weight average) Molecular weight 2000) 1.3 g Hydroxypropyl-β-cyclodextrin (Japan Food Processing Co., Ltd.) 0.15 g Polyethylene glycol # 2000 0.2 g Victoria Pure Blue BOH (Hodogaya Chemical Co., Ltd.) 0.08 g 2,4 -Bis (trichloromethyl) -6- (p-methoxystyryl) -s-triazine 0.1 g S-381 (Asahi Glass Co., Ltd., surfactant) 0.03 g cis-1,2-cyclohexanedicarboxylic acid 0.2g diethyl ketone / methyl lactate = 80/20 (weight ratio) 100 ml

(Photosensitive solution B) Novolak resin (phenol / m-cresol / p-cresol molar ratio 10/54/36, weight average molecular weight 4000) 5.4 g pyrogallolacetone resin (weight average molecular weight 3000) and o -Naphthoquinone diazide-5-sulfonyl chloride condensate (esterification rate 30%) 1.5 g Acrylic resin (HYPMA / AN / EA / MMA molar ratio 30/30 / 3.5 / 36.5, weight average) Molecular weight 2000) 1.3 g Hydroxypropyl-β-cyclodextrin (Japan Food Processing Co., Ltd.) 0.15 g Polyethylene glycol # 2000 0.2 g Victoria Pure Blue BOH (Hodogaya Chemical Co., Ltd.) 0.08 g 2,4 -Bis (trichloromethyl) -6- (p-methoxystyryl) -s-triazine 0.1 g S-381 (Asahi Glass Co., Ltd., surfactant) 0.03 g cis-1,2-cyclohexanedicarboxylic acid 0.2g of isobutyl acetate / methyl lactate = 80/20 (weight ratio) 100 ml

(Photosensitive Solution C) Novolak resin (phenol / m-cresol / p-cresol molar ratio 10/54/36, weight average molecular weight 4000) 5.4 g pyrogallol acetone resin (weight average molecular weight 3000) and o -Naphthoquinone diazide-5-sulfonyl chloride condensate (esterification rate 30%) 1.5 g Acrylic resin (HYPMA / AN / EA / MMA molar ratio 30/30 / 3.5 / 36.5, weight average) Molecular weight 2000) 1.3 g Hydroxypropyl-β-cyclodextrin (Japan Food Processing Co., Ltd.) 0.15 g Polyethylene glycol # 2000 0.2 g Victoria Pure Blue BOH (Hodogaya Chemical Co., Ltd.) 0.08 g 2,4 -Bis (trichloromethyl) -6- (p-methoxystyryl) -s-triazine 0.1 g S-381 (Asahi Glass Co., Ltd., surfactant) 0.03 g cis-1,2-cyclohexanedicarboxylic acid 0.2g of methyl isobutyl ketone / methyl lactate = 80/20 (weight ratio) 100 ml

(Photosensitive Solution D) Novolak resin (phenol / m-cresol / p-cresol molar ratio 10/54/36, weight average molecular weight 4000) 5.4 g pyrogallol acetone resin (weight average molecular weight 3000) and o -Naphthoquinone diazide-5-sulfonyl chloride condensate (esterification rate 30%) 1.5 g Acrylic resin (HYPMA / AN / EA / MMA molar ratio 30/30 / 3.5 / 36.5, weight average) Molecular weight 2000) 1.3 g Hydroxypropyl-β-cyclodextrin (Japan Food Processing Co., Ltd.) 0.15 g Polyethylene glycol # 2000 0.2 g Victoria Pure Blue BOH (Hodogaya Chemical Co., Ltd.) 0.08 g 2,4 -Bis (trichloromethyl) -6- (p-methoxystyryl) -s-triazine 0.1 g S-381 (Asahi Glass Co., Ltd., surfactant) 0.03 g cis-1,2-cyclohexanedicarboxylic acid 0.2g diethyl ketone / methyl cellosolve = 80/20 (weight ratio) 100 ml

(Photosensitive Solution E) Novolac resin (phenol / m-cresol / p-cresol molar ratio 10/54/36, weight average molecular weight 4000) 5.4 g pyrogallolacetone resin (weight average molecular weight 3000) and o -Naphthoquinone diazide-5-sulfonyl chloride condensate (esterification rate 30%) 1.5 g Acrylic resin (HYPMA / AN / EA / MMA molar ratio 30/30 / 3.5 / 36.5, weight average) Molecular weight 2000) 1.3 g Hydroxypropyl-β-cyclodextrin (Japan Food Processing Co., Ltd.) 0.15 g Polyethylene glycol # 2000 0.2 g Victoria Pure Blue BOH (Hodogaya Chemical Co., Ltd.) 0.08 g 2,4 -Bis (trichloromethyl) -6- (p-methoxystyryl) -s-triazine 0.1 g S-381 (Asahi Glass Co., Ltd., surfactant) 0.03 g cis-1,2-cyclohexanedicarboxylic acid 0.2 g methyl ethyl ketone / methyl isobutyl ketone / isobutyl acetate / ethyl cellosolve = 30/30/20/20 (Weight ratio) 100 ml

(Photosensitive Solution F) Novolak resin (phenol / m-cresol / p-cresol molar ratio 10/54/36, weight average molecular weight 4000) 5.4 g pyrogallolacetone resin (weight average molecular weight 3000) and o -Naphthoquinone diazide-5-sulfonyl chloride condensate (esterification rate 30%) 1.5 g Acrylic resin (HYPMA / AN / EA / MMA molar ratio 30/30 / 3.5 / 36.5, weight average) Molecular weight 2000) 1.3 g Hydroxypropyl-β-cyclodextrin (Japan Food Processing Co., Ltd.) 0.15 g Polyethylene glycol # 2000 0.2 g Victoria Pure Blue BOH (Hodogaya Chemical Co., Ltd.) 0.08 g 2,4 -Bis (trichloromethyl) -6- (p-methoxystyryl) -s-triazine 0.1 g S-381 (Asahi Glass Co., Ltd., surfactant) 0.03 g cis-1,2-cyclohexanedicarboxylic acid 0.2g of methyl cellosolve / ethyl cellosolve = 50/50 (weight ratio) 100 ml

Preparation of Photosensitive Lithographic Printing Plate Samples The coating solutions shown in Table 1 were applied onto the above support using a wire bar, and the photosensitive planographic printing plate samples 1 to 6 shown in Table 1 were coated.
It was created.

[0064]

[Table 1]

(Evaluation method) = Sensitivity = A step tablet for sensitivity measurement (Eastman Kodak No. 2, 21-step gray scale with a density difference of 0.15) was adhered to the sample, and a 4Kw metal halide lamp (large) was used. Nippon Screen Co., Ltd., “Vio Quick”
Was used as a light source and exposed from a distance of 90 cm. Next, this sample was developed at 27 ° C. for 20 seconds with a developer obtained by diluting SDR-1 (manufactured by Konica) developer 6 times with water. The sensitivity was defined as the exposure time at which 3.0 steps of the step tablet was completely cleared. Table 2 shows the results.

= Appropriate development conditions = (Difference in halftone dot sensitivity variation) A plate control wedge (UGRA
A 4 Kw metal halide lamp (Bio Quick manufactured by Dainippon Screen Co., Ltd.) was used as a light source and exposed for 20 seconds from a distance of 90 cm. Next, this sample was developed with a developer obtained by diluting SDR-1 (manufactured by Konica) developer 4 times, 5 times and 9 times with water at 27 ° C. for 20 seconds. Plate control wedge (UGR)
A PCW) is visually observed with a magnifying glass of 25 times for reproducibility of the circular patch. (The smaller the circular patch variation of UGRA PCW, the smaller the halftone dot sensitivity variation difference and the wider the range of suitable developing conditions.) The results are shown in Table 2.

= Printing durability = A step tablet for sensitivity measurement (Eastman Kodak No. 2, 21-step gray scale with a density difference of 0.15) was closely attached to the sample, and a 4Kw metal halide lamp (Dainippon Screen) was used. (Bio Quick Co., Ltd.)
Was used as a light source and exposed from a distance of 90 cm. Next, this sample was developed at 27 ° C. for 20 seconds with a developer obtained by diluting SDR-1 (manufactured by Konica) developer 6 times with water. The lithographic printing plate thus obtained was applied to a printing machine GTO manufactured by Heidelberg Co., Ltd., and coated paper, printing ink (New Bright Red manufactured by Toyo Ink Mfg. Co., Ltd.), and fountain solution (SEU-3 manufactured by Konica;
2.5%) was used for printing, and printing was continued until defective solidification of the image of the printed matter appeared or ink was non-printed in the non-image area, and the number of printed sheets at that time was counted. Table 2 shows the results.

[0068]

[Table 2]

[0069]

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a positive photosensitive composition and a photosensitive lithographic printing plate which have both high sensitivity, development tolerance and printing durability.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shinichi Matsubara 1 Sakura-cho, Hino-shi, Tokyo Konica Stock Company

Claims (3)

[Claims] 1. An (A) o-quinonediazide compound, (B)
Alkali-soluble resin and at least one selected from (C) diethyl ketone, isobutyl acetate, methyl isobutyl ketone, diethyl carbitol, 3-methoxy-1-butanol, dipropylene glycol monomethyl ether, methyl lactate, ethyl lactate, propylene A photosensitive composition comprising at least one mixed solvent selected from glycol monomethyl ether, diethylene glycol dimethyl ether, ethyl cellosolve and methyl cellosolve. 2. An (A) o-quinonediazide compound, (B)
Alkali-soluble resin and (C) methyl ethyl ketone, methyl isobutyl ketone, isobutyl acetate,
A photosensitive composition comprising a mixed solvent of two or more selected from ethyl cellosolve and methyl cellosolve. 3. A photosensitive lithographic printing plate comprising the photosensitive composition according to claim 1.